cpu_task.h

日本著名的的嵌入式实时操作系统T-Kernel的源码及用户手册。

/*
 *----------------------------------------------------------------------
 *    T-Kernel
 *
 *    Copyright (C) 2004 by Ken Sakamura. All rights reserved.
 *    T-Kernel is distributed under the T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.01.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2004/6/28.
 *
 *----------------------------------------------------------------------
 */

/*
 *	cpu_task.h (M32104)
 *	CPU-Dependant Task Start Processing
 */

#ifndef _CPU_TASK_
#define _CPU_TASK_

/*
 * System stack configuration at task startup
 */
typedef struct {
	W	acch;
	UW	accl;
	VW	r0_5[6];
	VW	r8_14[7];
	UW	psw;
	VP	bpc;
	VW	r6;
	VW	r7;
} SStackFrame;

/*
 * Size of system stack area destroyed by 'make_dormant()'
 * In other words, the size of area required to write by 'setup_context().'
 */
#define	DORMANT_STACK_SIZE	( sizeof(VW) * 4 )	/* To 'psw' */

/*
 * Size of area kept for special use from system stack
 */
#define	RESERVE_SSTACK(tskatr)	0

/*
 * Initial value for task startup
 */
#define	INIT_PSW	( PSW_BIE | PSW_BSM | PSW_SM )

/*
 * Create stack frame for task startup
 *	Call from 'make_dormant()'
 */
Inline void setup_context( TCB *tcb )
{
	SStackFrame	*ssp;

	ssp = tcb->isstack;
	--ssp;

	/* CPU context initialization */
	ssp->psw = INIT_PSW;		/* Initial PSW */
	ssp->bpc = tcb->task;		/* Task startup address */
	tcb->tskctxb.ssp = ssp;		/* System stack */
}

/*
 * Set task startup code
 *	Called by 'tk_sta_tsk()' processing.
 */
Inline void setup_stacd( TCB *tcb, INT stacd )
{
	SStackFrame	*ssp = tcb->tskctxb.ssp;

	ssp->r0_5[0] = stacd;
	ssp->r0_5[1] = (VW)tcb->exinf;
}

/*
 * Delete task contexts
 */
Inline void cleanup_context( TCB *tcb )
{
	/* None */
}

#endif /* _CPU_TASK_ */